The present invention relates to measurement of the amplitude of a length signal in viscoelasticity analysis of a sample.
In the prior art as shown in FIG. 3 the amplitude of a length signal is maintained sufficiently smaller than the effective measurement range of a peak measurement circuit and the amplitude is measured while it contains an offset.
The above-noted prior art has the drawback that a major part of the effective measurement span of the peak measurement circuit is provided for the offset, which thereby impairs the accuracy of the measurement of the amplitude.